1. By Maisa Mansour, MD Pulmonary medicine JUH
Pulmonary Embolism
By Maisa Mansour, MD
Pulmonary medicine
JUH

2. Definition
Blood clot, usually from the deep veins of the leg, also air, fat, tumor, that occludes pulmonary vasculature.

3. Epidemiology
PE is a major cause of death in the United States, with as many as 650,000 cases/yr
50,000 to 200,000 fatalities annually.
•>400,000 diagnoses of PE are missed in the United States annually.
•Most deaths from PE are due to failure to diagnose rather than failure to treat adequately.
•Two thirds of patients die within 1 hour of symptom onset; this is the golden hour.

4. Epidemiology Mortality is 15% within 3 months after occurrence
In 25% of PE, the initial manifestation is death

5. Risk Factors Virchow’s triad Stasis Venous injury/endothelial damage
Hypercoagulability
Most patients have several of these…

6. Risk Factors Inherited Acquired Factor V leiden
Prothrombin gene mutation
Low protein C, protein S, antithrombin III
Family history of VTE
Acquired
Age
Smoking
Obesity
immobility
Malignancy
Antiphospholipid antibody syndrome [venous and arterial]
Hyperhomocysteinemia [venous and arterial]
Oral contraceptive pills or hormone replacement therapy.
Atherosclerosis
Trauma, surgery, hospitalization
Infection
Long haul air travel
Electronic leads, indwelling catheters

7. Who gets Evaluated For Thrombophilia?
Patients in whom there is a high clinical suspicion for underlying disorder
PE not associated with acquired risk factor
Family history
Initial evaluation directed towards most common
Most common
Factor V Leiden
Prothrombin gene mutation
APL Ab syndrome
Hyperhomocysteinemia
Less common
Protein C&S deficiency, ATIII deficiency

8. Diagnosis
pathophysiology is complex and results in variable clinical presentation…

9. Acute PE: Pathophysiology
Gas exchange abnormalities
Right to left shunt
Leads to…
Hypoxemia
Increased A–a gradient.
V/Q mismatch.
Increased dead space
Respiratory alkalosis from hyperventilation
Often a sign of increased dead space and impaired minute ventilation
may suggest massive PE

10. Acute PE: Pathophysiology
Hemodynamic abnormalities
Depends on size of embolus
Increased vascular resistance/RV afterload
May cause RV dilation, then, FAILURE

11. Diagnosis Symptoms and Signs
Dyspnea
Chest pain (pleuritic)
Apprehension
Cough
Hemoptysis
Syncope
Palpitations
Wheezing
Leg pain
Leg swelling
Signs
Tachycardia
Tachypnea
hypoxemia
Accentuated S2
Fever
Diaphoresis
Signs of DVT
Cardiac murmur
Jugular venous distention
Cyanosis
Hypotension

12. Diagnosis Laboratory Evaluation
D-dimer
Non specific measure of fibrinolysis
High sensitivity (positive in presence of dz)
High negative predictive value (dz is absent when test is negative) in the outpatient setting
Useful in outpatient setting/emergency room, not an inpatient test for ruling out PE

13. Diagnosis Chest XR CXR Most often normal
May show collapse, consolidation, small pleural effusion, elevated diaphragm.

14. Diagnosis V/Q scans Old standard Currently reserved for
Renal impairment
IV contrast allergies
Pregnancy

15. Diagnosis VQ Scan Perfusion Ventilation Mismatch
Intro: Pulmonary Embolus
Diagnosis VQ Scan
Perfusion
Ventilation
Mismatch
Training Week April 2005 15

16. Diagnosis CT scan – New Standard
Data suggests CT is as accurate as invasive angiography (gold standard)
Negative predictive value of 99%
Quiroz et al, JAMA 2005

17. Diagnosis Spiral CT/ Multislice
Intro: Pulmonary Embolus
Diagnosis Spiral CT/ Multislice
Main Pulmonary Artery
Ascending Aorta
Descending Aorta
Rt Pulmonary Artery
Lt Pulmonary Artery
Thrombus
Training Week April 2005 17

18. Diagnostic algorithm Outpatient/ED Inpatient D-dimer normal Elevated
No PE
Chest CT
3rd gen scanner
Ist gen scanner
No PE PE
No PE PE
Ultrasound of leg veins
DVT No DVT
PAgram if continued clinical suspicion

19. ECHO for Risk Stratification
Insensitive for diagnosis but can risk stratify in patients with known PE
In normotensive patients RV dysfunction is an independent risk factor for early death

20. Risk stratification algorithm
Hemodynamically stable/no shock
Unstable/shock
BNP BNP (RV on CT)
Troponin troponin
(RV on CT)
ECHO
No RV dysfunction RV dysfunction
anticoagulation
Fibrinolysis, embolectomy

21. Treatment Anticoagulation
Mainstay of therapy
Unfractionated heparin .
LMWH (low molecular weight heparin).
More predictable response
No dose adjustments
Renally cleared. Some pts need adjustments
Kidney dz, pregnancy, massive obesity may need anti factor Xa monitoring
Usefulness questioned as correlation with antithrombotic effect not clear

22. Treatment Warfarin Vitamin K antagonist
Dose response variation may be in part attributable to the vitamin K epoxide reductase complex 1 (VKORC1)
Testing not usually performed

23. Treatment Thrombolytics
T-PA (alteplase) FDA approved for PE
100 mg infused over 2 hrs
no difference in mortality or recurrent PE at 90 days compared to UFH

24. Treatment Surgical embolectomy requires a specialized center
Can be safe
Can be effective
Small published numbers
Catheter directed embolectomy
Emerging as effective therapy when fibrinolysis cannot be used
Can be performed up to 5 days after event

25. Thank you